A known method for obtaining a refractory composite article based on at least one refractory compound, includes the following stages (U.S. Pat. No. 3,725,015):                Mixing of powder refractory material, boride and/or carbide, with a carbon-containing substance.        Molding of a blank in a predetermined shape out of the mixture.        Heating of the obtained blank for extraction of carbon out of the carbon-containing substance.        Impregnation of the blank with a molten metal alloy comprising 75-99% vol. of at least one metal out of the group containing Si, Cr, Fe, Ni, Ti and 1-25% vol. of a metal or mixture of metals out of the group Al, Cu, Fe and 0-24% vol. of a metal contained in the initial refractory material.        
This known method has a number of drawbacks. For instance, the use of organic substances as the source of carbon demands a high process temperature at the decomposition stage. Such decomposition occurs in the volume of the molded blank with release of great amount (up to 50% of bond mass) gaseous substances. It often causes defects (cracks) in the blank. Further more the use of reaction-active alloys at the impregnation means that, during the impregnation the alloy components interact with carbon and form solid carbides. The solid carbides block pores, thus impeding further impregnation as well as the formation of a pore less material with a uniform structure.
Another known method for obtaining a refractory composite material in the form of an article with predetermined shape is disclosed in Patent application PCT/EP97/01566 According to this method a porous blank, having a porosity of 20-60% vol., is being molded from a powder made out of a carbide-forming metal. Then the blank is being heat treated in atmosphere of gaseous hydrocarbon or hydrocarbon mixture at a temperature exceeding the temperature of their thermal decomposition until the weight of the blank has increased at least 3%. Next the semi-product is being impregnated with melt of a metal out of the group including the following metals: Ag, Au, Cu, Ga, Ti, Ni, Fe, Co or an alloy based on a metal out of this group.
As carbide-forming metal, a metal out of group IV, V or VI of the Periodic table is used, e.g. Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W. Heat treating is carried out in a hydrocarbonous atmosphere containing one or more hydrocarbons out of the group that comprises acetylene, methane, ethane, propane, pentane, hexane, benzene and their derivatives. As hydrocarbon mixture for heat treatment natural gas can be used. The scope of good properties allows the use of materials manufactured by this known method as refractory structural materials, erosion-resistant electrodes of plasmotrones, erosion-resistant heavy-current electric contacts, arc-suppressing elements, high-temperature heat accumulators, ablating heat-shielding materials and heat-resistant damping materials. As a rule, materials produced by this known method have a high specific density, which restricts the field of their application. When manufacturing an article according to this method, great care has to be given to the process parameters during the pyrocarbonization- and activation-heat treatments so that a distortion of the intermediate body, in form of warpage does not occur. The distortion that can occur is caused by the transformation of the carbide-forming agent to carbide, e.g. when Ti transforms to TiC.